Self locking and unlocking hinge

Abstract

A self locking hinge is disclosed which can index a door to multiple open positions and hold it in place. The door may be closed by opening it completely and then returning it to the closed position or by lifting the door to clear a portion of a locking mechanism and simultaneously closing it.

The invention claimed is: 
     
       1. A hinge arrangement comprising:
 a vehicle frame; 
 a door; 
 a first bracket rigidly attached to the vehicle frame, the first bracket comprising a locking area; 
 a second bracket rigidly attached to the vehicle frame, the second bracket comprising an unlocking area; 
 a third bracket rigidly attached to the door; and 
 a pin assembly attached to the third bracket, the pin assembly comprising a locking portion and an unlocking portion, the locking portion configured to contact the locking area as the door is rotated in a first direction, the locking area configured to hold the door in place when the locking portion contacts the locking area, the unlocking portion configured to contact the unlocking area as the door continues to be rotated in the first direction, the unlocking area configured to withdraw the locking portion as the door is rotated in a second direction and when the unlocking area is in contact with the unlocking portion. 
 
     
     
       2. A hinge arrangement comprising:
 a frame; 
 a door; 
 a first bracket having a locking area fixedly located with respect to the frame; 
 a second bracket fixedly located with respect to the frame and having an unlocking area; 
 a pin assembly fixedly located with respect to the door, the pin assembly having a locking portion and an unlocking portion, the pin assembly contacting the locking area and locking the door in place when the door is rotating in a first direction when it contacts the locking area, the unlocking portion and the unlocking area arranged to remove the locking portion as the door rotates in a second direction. 
 
     
     
       3. A hinge comprising:
 a frame; 
 a door; 
 a bracket fixedly located with respect to the frame; and 
 a pin assembly fixedly located with respect to the door, the pin assembly having a locking portion and an unlocking portion, the pin assembly contacting the locking area and locking the door in place when the door is rotating in a first direction when the locking portion contacts the locking area, the unlocking portion arranged to remove the locking portion as the door rotates in a second direction. 
 
     
     
       4. The hinge arrangement of  claim 1 , wherein the pin assembly is configured to bias the locking portion toward the locking area as the door is rotated in the first direction. 
     
     
       5. The hinge arrangement of  claim 4 , wherein the pin assembly comprises a spring and the spring is configured to bias the locking portion toward the locking area as the door is rotated in the first direction. 
     
     
       6. The hinge arrangement of  claim 1 , wherein the locking area is a first locking area, the first bracket comprises a second locking area, the locking portion is configured to contact the second locking area as the door is rotated in a first direction, the first locking area is configured to hold the door in a first position when the locking portion contacts the first locking area, the second locking area is configured to hold the door in a second position when the locking portion contacts the second locking area, and the unlocking portion is configured to contact the unlocking area after the door is rotated in the first direction beyond the first position and the second position. 
     
     
       7. The hinge arrangement of  claim 1 , wherein the locking area comprises a groove, the groove comprises a blocking surface on one end of the groove and a ramping surface on the opposite end of the groove, the blocking surface is configured to prevent the exit of the locking portion from the groove when the door is rotated opposite the first direction, and the ramping surface is configured to allow the exit of the locking portion from the groove when the door is rotated in the first direction. 
     
     
       8. The hinge arrangement of  claim 7 , wherein a first angle between an average slope of the blocking surface and a plane of rotation for the door is less than a second angle between an average slope of the ramping surface and the plane of rotation for the door. 
     
     
       9. The hinge arrangement of  claim 8 , wherein the second angle is obtuse. 
     
     
       10. The hinge arrangement of  claim 8 , wherein the first angle is either acute or right. 
     
     
       11. The hinge arrangement of  claim 8 , wherein the bottom of the groove is lower than the top of the groove such that the weight of the door exerts a force on the locking portion in the direction of the bottom of the groove. 
     
     
       12. The hinge arrangement of  claim 11 , wherein the pin assembly comprises a spring and the spring is configured to bias the locking portion toward the locking area as the door is rotated in the first direction.